The highlighting rules "NERDTreeClosable" and "NERDTreeOpenable" did
not recognize files beginning with a "~" character. This caused bad
highlighting on systems that use "~" and "+" for the dir arrow
symbols by default. Making these rules more specific solves this
problem.
The "~" characters in quickhelp section titles also would get
confused with a custom mapping for "~". Adjusting the
"NERDTreeHelpTitle" solved this problem.
I also changed the quickhelp title in a minor way to reflect the
proper spelling of "NERDTree".
d68c9abca8